Which of the following is a sign that a tourniquet might need to be tightened further?

The presence of bright red blood continuing to flow despite the application of a tourniquet is a crucial indicator that the tourniquet may need to be tightened further. Bright red blood typically signifies that the blood is being expelled under higher pressure from an arterial source. This indicates that the tourniquet is not effectively occluding the artery, which is essential in controlling severe bleeding from a limb injury.

In cases where bright red blood is observed, it suggests that the tourniquet is either too loose or improperly applied. Tightening the tourniquet further may help to achieve vascular occlusion and effectively control the hemorrhage.

Understanding blood color can also provide important clues about the type of bleeding: bright red blood is characteristic of arterial bleeding, while darker red blood is often associated with venous bleeding. Therefore, if bright red blood is observed despite initial tourniquet application, immediate action is necessary to re-evaluate and adjust the tourniquet to prevent severe blood loss and potential shock in the casualty.